Method and Device for Manufacturing Products having a Surface Provided with Embossments, and Products Obtained Thereby

ABSTRACT

A method for manufacturing a product having a surface provided with embossments, includes bringing a material web is in contact with a roller. The roller is provided with a relief at its surface, with which, via this relief, embossments are formed in the material web. The roller has a circumference of which, or at least certain parts thereof that are variable, or alternatively the circumference of the roller is variable by making use of embossing elements, wherein the mutual angular position thereof is adjustable.

This application is a continuation of U.S. application Ser. No.14/762,326 which claims the benefit under 35 U.S.C. 119(e) to the U.S.provisional applications No. 61/755,140 filed on Jan. 22, 2013 and No.61/759,112, filed on Jan. 31, 2013.

This invention relates to a method and device for manufacturing having asurface provided with embossments, as well as to products which areobtained by means of such method or device.

BACKGROUND 1. Field of the Disclosure

More particularly, the invention relates to a method and device formanufacturing floor covering products, and in particular floor panels,which comprise at least a substrate layer and a printed decor providedthereon, preferably in the form of a printed film provided thereon,wherein at least said substrate layer comprises a thermoplasticsynthetic material and preferably substantially consists of suchthermoplastic synthetic material.

2. Related Art

Such products, more particularly floor panels, are widely known as such.For example, this may relate to so-called vinyl tiles, also called LVT(Luxurious Vinyl Tiles). In such case, the thermoplastic material mostlyrelates to so-called soft PVC (polyvinyl chloride), or PVC comprising apercentage of plasticizers, as well as possible other additives. Herein,the printed decor may form a representation of a wood motif or stonemotif or any other motif, such as a fancy motif.

On the surface of such products, for example, said vinyl tiles, astructure may be provided, formed by embossments, such as a woodstructure, a stone structure, respectively. Other embossments may beapplied, too, for example, for imitating deeper-situated joints or thelike. Further, it is also known that such structure can be performed inregister with the printed motif, which in English is called “registeredembossed”. By such “registering” is to be understood that the structureis performed according to a motif which is adjusted to the printedmotif, and consequently the embossments cannot be provided randomly inrespect to the printed motif.

Thus, the difficulty with providing such embossments is maintaining theposition of the structure motif during the production processsufficiently in accordance with the printed motif, such that possibledeviations will not cumulate and/or the deviations will become sosubstantial that the intended effect will be impaired.

Various techniques for providing embossments, in other words,structuring a surface, are known from the state of the art, however,show various disadvantages, by which they seem to be less suitable inmore or less applications.

For example, it is known to realize embossments by means of chemicaltechniques, for example, by means of selectively foaming thermoplasticmaterial for forming a relief on the surface of the floor covering.However, relief realized by means of a chemical technique is hardlycontrolled and lacks definition.

According to another known technique, the surface is structured by meansof a roller provided with a relief, in other words, a roller having astructured surface. In order to maintain the structured surface of theroller approximately in register with the printed motif which is presenton the material web which has to be embossed or to be structured, thedisplacement performed by the surface of the roller is adjusted inrespect to the displacement performed by the material web, by eithersubjecting the roller to a slipping movement now and then, or by brieflywithdrawing the roller. It is clear that these techniques may have adisadvantageous influence on the appearance of the obtained product.Here, too, only extremely short contact times between the roller and thematerial web can be applied, with the disadvantage that the formedstructure often is not sufficiently fixed and the material of thematerial web will spring back elastically, certainly in the case whenthis material, at least in the case of thermoplastic material, alreadyhas cooled down more or less and thus is less permanently deformable.

According to another technique, the material web which has to bestructured or, thus, to be provided with embossments, is bent andpressed on along a roller which is provided with a relief. In thismanner, longer contact times can be realized, by which the embossmentsresulting therefrom will be better preserved. For maintaining theembossments in register with the printed motif, the material web, priorto contact with the roller, will be stretched to a greater or lesserextent. It is clear that, in order to be able to stretch the materialweb, this web must be sufficiently supple to allow this, as a result ofwhich this method is only suitable for relatively thin, sufficientlystretchable material webs. For example, with glass fiber-reinforcedvinyl, this technique is not applicable, as such vinyl is notsufficiently stretchable. Another disadvantage is that the material webhas to be subjected to additional tensions, which is not alwaysbeneficial to the product. Also, the setting and adjustment isrelatively difficult to control.

According to still another known technique, discontinuous pressingdevices are applied, which, however, results in a slow and expensivemethod.

SUMMARY OF THE DISCLOSURE

The present invention primarily aims at offering an alternativetechnique for manufacturing a product with a surface provided withembossments, in other words, a structured surface, wherein, according tovarious preferred embodiments thereof, also a solution is offered to theproblems with the method of the state of the art.

To this aim, the invention, according a first aspect thereof, relates toa method for manufacturing a product having a surface provided withembossments, wherein a material web is brought into contact with aroller, which roller is provided with a relief at its surface, withwhich, via this relief, embossments are formed in the material web,characterized in that for said roller use is made of a roller, thecircumference of which, or at least certain parts thereof, and moreparticularly the length of the circumference, is variable, are variable,respectively.

The variability of the circumference can be realized in various manners.According to a first possibility, this is achieved by, as mentionedherein above, realizing the roller such that the length of thecircumference is variable. However, other possibilities are notexcluded, and a second possibility thus will be described further in theintroduction, as well as in the detailed description.

By the relief, herein a structured surface has to be understood which ispresent on the surface of the roller. After the treatment by means ofthe roller then embossments are created in the surface of the materialweb which actually define a structured surface which substantially isthe negative of the structured surface of the roller.

By altering the circumference, more particularly the length of thecircumference, the distance over which the pattern formed by this reliefis repeating on the material web becomes smaller or larger, and theadvantage is obtained that an additional parameter is created forexerting an influence on the obtained result.

So, for example, the distance over which the impressed pattern isrepeating on the material web, in a simple manner can be adjusted to thedistance over which the print present on the material web is repeating,as a result of which both, seen on average, can be brought to mutualconformity. In a preferred embodiment, the method then is alsocharacterized in that, via the relief, embossments are realized whichare in register with a printed motif present on the material web,wherein the position of the relief in respect to the printed motif isadjusted by adapting said circumference, and more particularly thelength of the circumference of the roller. In this manner, then alsoso-called “registered embossed” products can be realized, starting froma continuous material web, wherein an adjustment between the positionsof the printed motif and the embossment motif can be realized withouthaving to stretch the material web.

According to a preferred embodiment, the material web herein is realizedat least, on the one hand, by forming a substrate and, on the otherhand, laminating a decor layer, which is made as a film and comprisesthe printed motif, on the substrate, wherein further preferably atransparent wear layer is provided, too. The decor layer consists, forexample, of a sheet of synthetic material which is printed on its decorside. This allows first realizing the decor layer separately by means ofa printing technique.

In the case that the method is applied for realizing products whichcomprise embossments which are in register with the printed motif, theposition of the relief in respect to the printed motif preferably isautomatically adjusted during performing the method, such by anadjustment performed on the circumference of the roller, for example, byaltering, as aforementioned, the length of the circumference. In thismanner, a continuous production can be maintained. Herein, theadjustment can be performed by means of detection of the printed motifand/or of marks and by comparing the location thereof with the positionof the relief on the web, or by comparing it with the location of theobtained embossments. Preferably, the adjustment of the roller iscontrolled on the basis of data derived from the material web whichstill has to be provided with embossments, more particularly from theposition of the printed motif.

Preferably, the material web is bent around the roller, such that thecooperation between relief and material web will take place at leastover an arc-shaped part. In this manner, a relatively long contact timecan be realized, as a result of which the embossments, after being made,thus, when releasing from the roller, usually will retain at least 80%of their structure depth, at least in a number of important applicationsof the invention, such as in the production of vinyl-based floorcovering materials, or similar floor covering materials based on elasticsynthetic material.

More particularly, it is preferred that the material of the material webmoving along the roller is kept in contact with the roller for at least3 seconds and still better at least 5 seconds.

In practice, preferably a roller is applied which is provided with oneor more embossing elements, preferably segment-shaped and moreparticularly arc segment-shaped embossing elements arranged along thecircumference thereof, which comprise said relief, between which one ormore intermediate spaces are present, and wherein the circumference isvariable and is varied by varying one or more of the intermediatespaces. The intermediate spaces then preferably will be chosen such thatthey coincide with technical zones present between the embossmentmotifs.

According to one of the possibilities, at least two segment-shapedembossing elements are applied. In practical terms, these are two, threeor four. On the one hand, in this manner an adequate adjustment can beprovided, whereas at the same time still a roller with a not tooextensive diameter can be applied.

Preferably, a roller is applied, the circumference of which is variablein that the length of the circumference is variable, or at least thelength of one or more parts thereof is variable. According to anotherpreferred characteristic, a roller is applied which is provided with oneor more arranged along the circumference thereof segment-shaped,preferably arc segment-shaped, embossing elements comprising saidrelief, between which one or more intermediate spaces are present andwherein the length of the circumference is altered and adjusted byvarying one or more of said intermediate spaces.

In a specific embodiment of the invention, one or more and preferablyeach of the segment-shaped embossing elements are substantially radiallydisplaceable, either together or each apart. It is clear that in thismanner a larger or smaller average radius of the roller can be provided,as a result of which the length of the circumference of the rolleralters and the intended effect can be realized.

In combination with the first aspect, the method further can becharacterized in that for the roller use is made of a roller withreplaceable elements, more particularly said segment-shaped embossingelements, providing the relief. In that the embossing elements have tobe made displaceable, they are also suitable for being made replaceable.Such replaceability is useful for replacing defect or worn-out embossingelements, as well as for modifying the device for other embossmentmotifs. The replaceable elements can be formed by exchangeable pressplates.

The method of the invention, described herein above as well as hereinbelow, preferably is applied for forming embossments in a material webwhich consists of synthetic material or is made on the basis ofsynthetic material, or which comprises one or more top layers ofsynthetic material, primarily there where embossments have to be made ina surface thereof, which embossments are in register with a printedmotif.

Primarily with material webs where at least the upper material portion,which has to be provided with embossments, comprises a plasticallydeformable synthetic material, the invention will show its advantagesbest, in particular as the technique enables a relatively long contactbetween the roller and the material web, as the material web is kept incontact with the roller over a certain arc length.

Said method is primarily intended and suitable for being applied in theproduction of floor covering material of synthetic material, moreparticularly supple synthetic material. In particular, it is intendedfor being applied for the production of floor covering material on thebasis of vinyl, and more in particular for the production of so-calledLVT tiles (Luxurious Vinyl Tiles) or similar tiles on the basis ofsynthetic material.

Said material web preferably consists of a continuous material web,which, after providing the embossments, is cut to form smaller parts,for example, panels, more particularly floor panels, for example, saidLVT. On at least a number of the edges of the panels, more particularlyfloor panels, coupling parts may be formed allowing that a plurality ofsuch panels can be coupled to each other, wherein the coupling partsprovide for a locking in a direction perpendicular to the plane of thepanels, as well as in a direction in the plane of the panels andperpendicular to the edges concerned.

According to a particular embodiment, the material web is supplied tothe roller in a heated condition and the roller is cooled. Hereby, thematerial fed on the roller can be provided with embossments in a smoothmanner, at least when this relates to thermoplastic material, whereasthe subsequent cooling ensures that a fixing of the structure isobtained.

The invention also relates to a device for performing the method of theaforementioned, and below explained further, first aspect of theinvention. To this aim, it relates to a device for manufacturing aproduct having a surface provided with embossments, with a processingstation for forming embossments, wherein a material web is brought intocontact with a roller, which roller is provided with a relief on itssurface, by which via this relief embossments are formed in the materialweb, characterized in that for said roller use is made of a rollerhaving a variable circumference.

According to a first possibility, the circumference of the roller isvariable in that the length of the circumference can be altered.

According to a second possibility, the circumference is variable in thatthe roller consists of at least two embossing elements having a variablemutual angular position. This second possibility will be explained ingreater detail further below.

Preferably, this device is further characterized in that it comprises anadjustment system with which, in the case that a relief is used which isintended for being in register with a printed motif present on thematerial web, the position of the relief in respect to the printed motifis adjusted, this by adapting the circumference of the roller, whereinthis adjustment system preferably provides for an automatic adjustment.

In a practical embodiment, the device, downstream of said processingstation, comprises a production unit in which the material web, or atleast a substrate of this material web, is produced. The use of suchroller in fact allows an easy application thereof in combination withsuch production unit.

According to a second independent aspect, the invention also relates toa method for manufacturing a product having a surface provided withembossments, wherein a material web is brought into contact with aroller, which roller is provided with a relief on its surface, by whichvia this relief embossments are formed in the material web, with thecharacteristic that for said roller, use is made of a roller which isprovided with one or more replaceable embossing elements which areprovided with said relief. Preferably, said embossing elements areformed by exchangeable press plates which are provided on thecircumference of the roller, wherein these may be, for example,exchangeable as such or together with supports on which they areprovided. According to an alternative, more solid elements are appliedin which the relief is directly provided.

The method of the second aspect also shows its advantages best in theproduction of floor covering material of synthetic material, and moreparticularly floor covering material selected from:

-   -   floor covering material of supple synthetic material;    -   floor covering material on the basis of vinyl;    -   floor covering in the form of so-called LVT tiles (Luxurious        Vinyl Tiles), or similar tiles.

The invention also relates to a device by which the method of the secondaspect can be realized. Thus, it also relates to a device formanufacturing a product having a surface provided with embossments, witha processing station for forming the embossments, wherein a material webis brought into contact with a roller, which roller is provided with arelief on its surface, by which via this relief embossments are formedin the material web, characterized in that the roller is provided withone or more replaceable embossing elements which are provided with saidrelief.

It is clear that the invention also relates to products, moreparticularly floor covering products, and in particular floor panelswhich are obtained by means of a method or device as described hereinabove. According to a preferred application, this relates to so-calledLVT tiles or similar products manufactured on the basis of syntheticmaterial.

It is noted that the invention primarily is intended for being appliedfor manufacturing floor panels of synthetic material, more particularlyof the LVT type or the like. The fact that said intermediate spaces varydue to adjusting the roller and/or that there are intermediate spacesbetween the exchangeable embossing elements, does not form a problemhere, as those can be made to coincide with technical spaces, where, forexample, after the floor panels have been formed by cutting them,coupling parts have to be formed at the edges.

It is noted that per segment-shaped embossing element a plurality offloor tiles can be embossed.

Although the invention is particularly suitable for being applied, asaforementioned, in the manufacture of floor panels, it is not excludedto use them, according to said first aspect as well as to said secondaspect, in a supple floor covering, preferably on the basis of vinyl,which is intended for being marketed on a roll, wherein the printedmotif and the embossments to be realized then will be adapted to eachother in such a manner that the transitions at the possible intermediatespaces are acceptable.

According to an important preferred characteristic of the first as wellas of the second aspect of the present invention, use is made of aroller having a relatively large diameter, preferably of at least 60centimeters, and still better larger than 1 meter. This offers theadvantage that a small radial displacement of the embossing elementsswiftly results in a noticeable enlargement of the circumference length,such that a smooth adjustment is possible. These minimum diameters arealso useful for obtaining that the material web to be treated does nothave to be subjected to an extremely sharp bending, which in its turnstill allows smoothly bending relatively stiff material webs, such asvinyl substrates reinforced with a glass fiber layer or the like, over acertain arc length along the surface of the roller, even if the materialweb is structured in cold or almost cold condition, which means onambient temperature. Such relatively large diameters also offer theadvantage that a relatively large structured surface is obtained inpassage direction, such that smoothly a plurality of embossing elementscan be provided in circumferential direction on the roller. Irrespectivewhether one or more embossing elements are provided, the advantage willalso be obtained that the motif of the structure will be repeated over arelatively large length only, such that a relatively large variety of,for example, vinyl tiles can be realized.

In the case of the first aspect, it is clear that the dimension by whichthe length of the circumference must be able to vary is chosen such thatsufficiently large changes can be performed, such that the position ofthe relief in respect to the printed motif can always be brought intomutual conformity. It is clear that the dimension of the interval overwhich changes must be able to be performed can be determined by theperson skilled in the art. With diameters of more than 1 meter,preferably an adjustment possibility is provided which is at leastseveral millimeters, however, still better is 2 to 3 centimeters.

It is noted that the floor panels or tiles, more particularly the motifsthereof, can be provided on the circumference of the roller in at leasttwo manners, either with their longitudinal direction according to thecircumferential direction of the roller, or with their longitudinaldirection in axial direction of the roller. With motifs wherein thestructure substantially extends in the longitudinal direction of thefloor panels, for example, with wood motifs, it is preferred that themotifs are performed with their longitudinal direction according to thecircumferential direction of the roller, as this offers the advantagethat possibly enclosed vapors or air are pressed away more smoothly frombetween the material layer and the roller and thereby have nodisadvantageous impact on the structuring.

As described herein above, according to the first aspect use is made ofa roller of which the circumference, or at least certain parts thereof,are variable. Herein above, it was explained that this, moreparticularly, thus, in a particular embodiment, is the length of thecircumference which is variable, such by altering, for example, thediameter of the roller or at least radially displacing certain partsthereof.

It is noted that, as already explained above, by a roller with a“variable circumference” not exclusively an alteration of thecircumference length and/or diameter has to be understood. Also otherkinds of alterations taking place at the circumference of the roller areto be considered, in as much as such adaptations, of course, will resultin the fact that the location of the embossments can be adapted inrespect to a motif, in particular a printed motif.

According to a particular preferred embodiment, which forms a secondpossibility of the first aspect of the invention, two or more embossingelements located along the circumference are applied, wherein the mutualangular position between at least two and preferably all successiveembossing elements is variable and adjustable, preferably withouttherein having to perform a radial displacement. In this manner, eachtime the first subsequent embossing element which has to come intocontact with the material web can be altered in angular position inrespect to the preceding embossing element for adjusting in this mannerthe distance between the successive embossment patterns, preferably infunction of the printed motif. It is clear that in this manner a simple“registered embossing” can be achieved.

The mutual angular position can be realized in any manner. Preferably,the embossing elements each are driven separately, for example, by meansof servo motors, and in this manner are positioned in mutual respect.According to another possibility, the mutual positioning is performed bymeans of positioning means which are active between the rotatingembossing elements.

Preferably, herein only two embossing elements are applied, which thuseach cover approximately half a circumference. However, the applicationof more than two, for example, three or four embossing elements is notexcluded. It is clear that the embossing elements in such case, too,preferably are realized as segment-shaped, preferably arcsegment-shaped, elements.

Preferably, each embossing element is balanced, either entirely orpartially balanced.

The technique making use of the angular rotation instead of a radialdisplacement offers the advantages that a more robust support ispossible and no radial forces have to be created during adjustment.Another advantage is that no radius differences occur at thecircumference.

It is clear that the technique making use of the angular rotationinstead of a considerable alteration of the length of the circumferenceof the roller, can also be applied in combination with one or more ofthe characteristics already described herein above, in as much as suchcombination does not comprise any contradictory characteristics. Herein,this relates, on the one hand, to the characteristics relating to theroller itself and the arrangement thereof, such as the fact whether ornot exchangeable embossing elements are applied, the fact that a heatingand cooling is provided, the fact that embossing elements are appliedwhich are arc segment-shaped, the fact that the material web is fedaround a portion of the circumference, and so on, as well as, on theother hand, the characteristics relating to the fields of application,in other words, for example, for the production of material webs on thebasis of synthetic material and in particular the production ofvinyl-based floor panels and the like, and so on.

The invention, according to said first as well as said second aspect,also is particularly useful for forming embossments in a material webwhich consists of a multi-layered sheet-like material, preferably with aprinted motif, and the method thus is applied for forming embossments onthe surface which preferably are in register with the motif. Within thescope of such application, the method thus can be applied formanufacturing a structured film or a structured laminate sheet, withembossments which preferably are in register with the motif. Up to thepresent, such laminate sheets were difficult to provide with anembossment motif which is in register with the printed motif, certainlynot in a continuous production process. The technique of the invention,however, allows this. Thus, the finally cut therefrom laminate sheetsthen can be applied by furniture makers, interior installers and thelike, for example, for being glued on a supporting structure. In suchlaminate sheets, use can be made of thermoplastic materials, such asPVC, as well as thermo-hardening materials, such as resins, for example,melamine resins, wherein carrier sheets for the synthetic material, suchas paper, may or may not be employed.

Consequently, the technique of the invention can also be applied in theproduction of so-called HPL (High Pressure Laminate) and CPL (CompactLaminate).

Finally, it is noted in general that by a “roller” in the broadest sensea rotatable element has to be understood, irrespective whether theglobal contour thereof is formed by separate elements or not, which intheir turn then can be separately rotatably supported or not.

Generally stated, a roller according to the invention can also bedefined as a roller which is provided with means by which the distanceover which embossment patterns made by this roller can be altered bychanges in the roller itself, such preferably by providing an adjustmentpossibility with which the intermediate distance between two or moresuccessive embossing elements can be altered. If only one embossingelement is applied, which extends along the circumference of the roller,the intermediate distance between the beginning and end can be adjustedin order to realize the invention.

Further characteristics will become clear from the detailed descriptionand claims following below.

BRIEF DESCRIPTION OF THE DRAWINGS

With the intention of better showing the characteristics of theinvention, herein after, as an example without any limitative character,some preferred embodiments are described, with reference to theaccompanying drawings, wherein:

FIG. 1 schematically represents an embodiment of the method according tothe invention, as well as schematically illustrates a device accordingto the invention applied for this purpose;

FIG. 2 represents a variant to the embodiment of the roller;

FIGS. 3 and 4 in a schematic manner represent two drive systems whichcan be applied in a roller according to the first aspect of theinvention;

FIG. 5 strongly schematized represents another variant of the embodimentof FIG. 2;

FIGS. 6 and 7 schematically represent two possibilities of embodimentsof the second aspect of the invention;

FIGS. 8 to 16 still relate to a number of variants of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 1, schematically a method is represented for manufacturing,according to the invention, a product 1 having a surface 3 provided withembossments 2, wherein a material web 4 is brought into contact with aroller 5, which roller 5 is provided with a relief or structure 7 on itssurface 6, in other words, a profiled surface, wherein said embossments2 are formed in the material web 4 via this relief.

In the represented example, the material web consists of a substrate 8and at least a decor layer 9 which is made as a film and is laminated onthe substrate and which comprises a printed motif 10. Moreover,preferably also a transparent wear layer 11 is provided on top of thewhole, which wear layer preferably also comprises thermoplasticsynthetic material.

Herein, the roller 5 forms the most important part of a processingstation 12 for forming the embossments 2. The substrate 8 can besupplied prefabricated from a reel or the like or can also be producedupstream of said processing station 12 in a production unit 13, eitherby forming the substrate 8 there from a basic material substantially onthe basis of synthetic material, for example, synthetic materialpellets, or by laminating various prefabricated layers on top of eachother, or also by forming a substrate by means of a so-called gellingprocess. According to variants, other manufacturing techniques for thesubstrate are not excluded. The printed decor layer 9 and the wear layer11 are laminated on the substrate and can be supplied from notrepresented supply reels. Lamination can take place by means of mutualfusion and/or by the intermediary of additionally added substances, suchas plastisols, or also in any other manner. In consideration of the factthat various known techniques are possible, providing the decor layer 9and the wear layer 11 on the substrate is illustrated in a schematicmanner only.

The particularity of the invention consists in that for the roller 5,use is made of a roller, of which the circumference, and in this casethe length of the circumference, is variable, such that with lengthvariations occurring in the printed motif 10, which means that thedistance over which a motif is repeated, will vary, also the averagelength over which the relief 7 extends per rotation can be adapted, insuch a manner that the relief 7, seen on average, remains in registerwith the passing printed motif 10.

In the example, for this purpose use is made of a plurality, in thiscase three, of segment-shaped embossing elements or structuring elements14, which are arranged along the circumference and can be moved radiallyapart, with the consequence that the total circumference thereof altersin size in that the intermediate spaces T then also change. The radialdisplacement is indicated by arrows R. This displacement can be realizedin any manner and, as schematically represented, is performed by a drivesystem 15 integrated in the roller 5. This drive system 15 preferably iscontrolled automatically on the basis of, for example, either a feedforward 16 or a feedback 17. Herein, by means of a sensor or any otherdetection mechanism, 18 and 19, respectively, a control is performed onthe location of the print, possibly by means of marks provided in thedecor layer 9, after which the circumference of the roller 5 is adjustedin function hereof and by means of the drive system 15.

As described in the introduction, the material web 4 preferably is bentaround the roller 5, such that the cooperation between the relief 7 andthe material web 4 is performed at least over an arc-shaped part B, bywhich a longer contact of preferably at least three seconds ismaintained between the surface of the roller and the material web 4.

In the example, the pressing on and bending over the roller 5 isperformed by means of a roller 20, preferably with a relatively softsurface, for example, of rubber, and a bending roller 21, which mayconsist of any material. It is clear that possible other pressing onmeans can be applied, or also additional pressing on means, such as therepresented rollers 22, may be applied.

As mentioned in the introduction, the material web 4 possibly can besupplied to the roller in a more or less heated condition, either withresidual heat originating from a preceding manufacturing process, or bypreceding heating, whereas the whole is cooled during providing theembossments, preferably via a cooling of the roller 5, in this case bymeans of a cooling liquid flowing through a cooling circuit 23 of theroller.

Subsequently, the final product possibly may be cut to smaller pieces,such as, for example, LVT tiles 24.

Possibly, a glass fiber reinforcement layer 25 can be incorporated intothe substrate.

It is noted that the various layers of the material web 4 arerepresented schematically. In reality, the layers 9 and 11 are thinfilms, whereas the substrate 4 determines the fundamental thickness.Backing layers may be applied, too.

In the case of vinyl or the like, the material web 4 preferably has athickness of 2 to 6 mm.

It is noted that the segment-shaped embossing elements 14 do notnecessarily have to be radially displaced in a simultaneous manner, butthat they can also be controlled separately, for example, in that eachsegment, immediately before coming into contact with the material web,is brought into the desired radial position.

It is also clear that the roller 5 preferably is driven by a notrepresented motor. Also, the rollers 20-21 may or may not be driven.

In FIG. 2, a similar roller 5 is represented schematically, however,having only two instead of three segment-shaped embossing elements 14.

In FIG. 3, a mechanical drive system for displacing the segment-shapedembossing elements 14 is represented schematically, which systemconsists of lever arms 26 carrying the segment-shaped embossing elementson one extremity 27 and which can be displaced on their otherextremities 28 via a spindle system 29. The spindle system is driven viatransmission elements 30-31-32 by means of a servo motor 33. Thetransmission system is illustrated for one embossing element 14 only,however, it is clear that via the same servo motor 33 and respectivecoupled thereto transmission means a plurality of embossing elements canbe driven simultaneously.

Driving the roller 5 is performed by means of the motor 34.

Generally, it can be stated that the above-described rollers 5 can bemade with any axial length L. A practical length is from one meter toseveral meters.

In FIG. 4, a variant is illustrated with conical elements 35 which, byan axial drive and displacement A thereof, provide for a radialdisplacement R on the embossing elements 14, by working in conjunctionwith parts 36 thereof.

FIG. 5 shows in a strongly schematized manner that the enlargement ofthe circumference can also be realized with only one segment-shapedembossing element 14, which, for example, can be pressed open, asschematically represented.

In FIG. 6, the second aspect of the invention is representedschematically, wherein the roller 5 is provided with one replaceableembossing element 14, in this case in the form of a press plate which istensioned around a basic part 37. In principle, this tensioning can beperformed in any manner. A practical possibility consists in that, asschematically illustrated, the press plate, on one extremity, is fixedlyhooked in a seat via a formed thereon hook-shaped part 38, and on theother extremity is clamped into a seat by means of another attachmentelement 39.

FIG. 7 schematically represents another possibility of the secondaspect, wherein a plurality of segment-shaped embossing elements 14 areprovided on a basic part 37 in an exchangeable manner. In this case,they can be mounted and dismounted, for example, by means of an axialmovement over the basic part 37.

It is clear that the first and the second aspect can also be combined,for example, by working in FIGS. 1 through 5 with replaceable embossingelements or partially replaceable embossing elements. So, for example,may parts 40 be used, which form a carrier for parts 41, for example, inthe form of a press plate, which latter then function as the actualembossing parts, wherein the parts 41 are replaceable in accordance withthe second aspect of the invention.

Also, in respect to the methods as well as in respect to the devices,all herein above-described operations and components pertaining to thefirst aspect may also be applied in the second aspect and reverse; suchin all possible combinations, in as far as such combinations are notcontradictory.

In FIGS. 8 and 9, schematically an important variant of the first aspectof the invention is represented, wherein, as aforementioned, anadjustment is provided of the mutual angular position about axis X ofthe embossing elements 14, in this case arc segment-shaped embossingelements.

In the example of FIGS. 8-9 two approximately half-cylindrical embossingelements 14 are used. In the condition of FIG. 8, those are in positionssituated precisely diagonally opposite, with equal intermediate spacesor intermediate distances T1 and T2. If now a larger “repeat” distanceis necessary, for example, by a larger stretching, the distance T1 canbe enlarged by providing a suitable mutual angular adjustment and, asillustrated in FIG. 9, applying a larger distance T1 before theembossing element, which as next has to be brought into contact with thematerial web 4, actually contacts the material web. Thus, 14B isadjusted in respect to 14A about the axis X. After then only 14B is incontact with the material web, 14A in its turn can be positioned inrespect to 14B in order to then adjust the desired distance T2.

Of course, this all can take place with the necessary controls and in avariety of applications, analogous as herein above described in theintroduction or by means of FIGS. 1 to 7.

Each embossing element 14 can be driven by a separate motor, forexample, servo motor, and/or be controlled by means of mutual drives.However, other driving systems are not excluded. In consideration of thefact that the drives are of any kind, they are not specificallyillustrated in FIGS. 8 and 9 as well as in the FIG. 10 described below.

FIG. 10 shows that the whole can be balanced with counterweights42A-42B, preferably for each embossing element.

It is clear that in all embodiments the embossing elements 14 can becooled.

FIGS. 11 to 16 represent, strongly schematized, still a number of otherembodiments, wherein use is made of mutually rotatable embossingelements about axis X, herein below also called segments. Herein, threesegments are represented; however, other numbers are not excluded,either.

In FIGS. 11 and 12, an embodiment is represented with springs as well aspositioning systems, for example, servos or the like, between thesegments or embossing elements I-II-III. Possibilities without springsare possible, too, as explained further on. In FIG. 11, servo PA isswitched on and positions segment II so far in respect to segment I thatthe embossments remain in register with the decor. Servos PB and PC arenot active and segment III is being centered by means of the springsbetween the segments I and II. When segment I leaves the material web,as in FIG. 12, servo PA is switched off and segment I centers between IIand III. Then servo PB has to be switched on for positioning segment IIIin respect to II, and so on. Of course, a general drive is there, too.

FIG. 13 makes clear that the centerings and springs are not necessary.One can also work with control means only, such as servos PA-PB-PC orhydraulic positioning systems and the like, which then each have toprovide for the appropriate mutual displacements. The general rotationalmovement has to be performed via, for example, a drive in the region G.

Instead of using a general drive G, separate main drives can be used aswell. FIGS. 14 and 15 schematically illustrate an example. Via supportsS-I and S-II, the segments or embossing elements I and II are freelyrotatable supported on the shaft and each are rotated around the shaftby motors M1 and M2, for example, servo motors. The supports S-III ofsegment III are fixedly provided on the shaft, which is driven via motorM3. By simultaneously driving the motors M1-M2-M3 and appropriatelyproviding for a mutually advanced or delayed movement, the distancebetween two segments successively contacting the material web can be seteach time.

FIG. 15 is a schematized cross-section according to line XV-XV in FIG.14. The embossing element III is not represented in FIG. 14, inconsideration of the fact that it is situated on the rear side.

FIG. 16 represents a variant with a central shaft, which can be a largehollow shaft which, via a motor M, provides for the general rotation.The segments I-II-III are made as shells, which are mutuallydisplaceable in order to adjust the intermediate space of the shellwhich then starts contacting the material web and the preceding shell,by means of drives, such as servos PA-PB-PC. This is possible, forexample, in that the servos cooperate with a gearwheel TA, whichcooperation determines the position of each segment in respect to theshaft.

It is clear that said segments I-II-III form the herein above-mentionedembossing elements 14.

It is noted that, although in FIGS. 8 to 10 only schematically one layerfor the material web 4 is represented, whereas in FIGS. 11 to 16 nomaterial web is represented, the technique described by means of thesefigures can also be applied in combination with everything described inthe introduction as well as by means of FIGS. 1 to 2.

Substantially, FIGS. 5 to 16 aim at describing a roller which appliesthe technique of the invention and thus also can be applied in aproduction process according to FIG. 1.

As known, by LVT tiles square tiles as well as rectangular plank-shapedtiles may be understood.

The printed motif can imitate a well-defined material, such as wood orstone, but may also be a fancy motif.

In the case that the motif represents wooden planks, these may besituated with their longitudinal direction parallel to the longitudinaldirection of the material web as well as transverse thereto. Theembossment motifs on the roller then are directed circumferentially oraxially, respectively.

It is noted that the technique of the invention for bringing theembossments into register with the printed motif and maintaining it likethis, possibly can also be combined with other techniques aiming at thesame effect. Such other techniques are, for example, the controlledstretching of the decor layer prior to the lamination thereof and/or thecontrolled stretching of the entire material web prior to feeding it tothe roller.

Herein above, the “intermediate spaces” and “intermediate distances”form identical terms. When these are “varied” or “altered”, it is meantthat the distance thereof is altered in circumferential direction. Thus,an “intermediate space” does not necessarily have to be considered acompletely open space, but substantially only aims at an interval whichis present between two embossing patterns, or between the beginning andend of the same embossing pattern.

The present invention is in no way restricted to the embodimentsdescribed by way of example and represented in the figures; on thecontrary, such methods and device can be realized according to variousvariants, without leaving the scope of the invention.

1. A method for manufacturing a product having a surface provided withembossments, comprising the steps of: bringing a material web intocontact with a roller, the roller having a variable circumference and arelief at a surface of the roller; forming one of the embossments in thematerial web by the relief of the roller; placing the embossment inregister with a printed motif present on the material web; automaticallyadjusting a position of the relief in respect to the printed motif byvarying the variable circumference; wherein the roller has at leastfirst and second segment-shaped embossing elements, arranged along thevariable circumference thereof and defining the relief, at least firstand second intermediate spaces disposed about the variable circumferencebetween the at least first and second segment-shaped embossing elements;wherein the at least first and second segment-shaped embossing elementsare automatically angularly adjusted relative to one another by rotatingone of the at least first and second segment-shaped embossing elementsrelative to another one of the at least first and second segment-shapedembossing elements about an axis of the roller according to the printedmotif, said at least first and second intermediate spaces definingdistances relative to one another according to an angular adjustment ofthe at least first and second segment-shaped embossing elements.
 2. Themethod of claim 1, wherein in a first condition the at least first andsecond intermediate spaces have generally a same value, wherein in asecond condition such that the first segment-shaped embossing element isangularly adjusted about the axis at a first angle relative to thesecond segment-shaped embossing element, the at least first and secondintermediate spaces have different values.
 3. The method of claim 1,comprising the step of performing the angular adjustment by detection ofthe printed motif.
 4. The method of claim 1, further comprising the stepof bending the material web around the roller, such that cooperationbetween the relief and the material web is over an arc-shaped profile.5. The method of claim 1, wherein the at least first and secondsegment-shaped embossing elements each define an arc-shape.
 6. Themethod of claim 5, wherein the at least first and second segment-shapedembossing elements have a same shape and a same length.
 7. The method ofclaim 5, wherein the at least first and second segment-shaped embossingelements are arranged diagonally opposite one another.
 8. The method ofclaim 5, wherein the at least first and second segment-shaped embossingelements are each driven by a separate motor and correspondingly rotatedabout the axis relative to one another.
 9. The method of claim 1,further comprising the step of supplying the material web, or at least asurface thereof to be provided with the embossments, to the roller in aheated condition, and arranging the roller in a cooled condition. 10.The method of claim 1, wherein the material web comprises syntheticmaterial.
 11. The method of claim 1, wherein the material web comprisesa continuous material web, which, after providing the embossments, themethod further comprises the step of cutting the continuous web intofloor panels.
 12. The method of claim 1, wherein the angular adjustmentof each of the at least first and second segment-shaped embossingelements is realized by a drive system integrated in the roller andcontrolled automatically on the basis of feed forward or feedback of thematerial web.
 13. The method of claim 12, wherein a sensor or adetection mechanism acts on a location of the printed motif after whichthe variable circumference of the roller is adjusted as a function ofdetection by the sensor or the detection mechanism and by the drivesystem.
 14. The method of claim 1, wherein the angular adjustment of thefirst segment-shaped embossing element includes the step of rotating thefirst segment-shaped embossing element about the axis such that a firstend of the first segment-shaped embossing element is closer to a secondend of the second segment-shaped embossing element than a second end ofthe first segment-shaped embossing element to a first end of the secondsegment-shaped embossing element.
 15. The method of claim 14, whereinthe first intermediate space is defined between the first end of thefirst segment-shaped embossing element and the second end of the secondsegment-shaped embossing element, and the second intermediate space isdefined between the second end of the first segment-shaped embossingelement and the first end of the second segment-shaped embossingelement, the first intermediate space having a shorter length than thesecond intermediate space.
 16. A method for manufacturing a producthaving a surface provided with embossments, comprising the steps of:bringing a material web into contact with a roller, the roller having avariable circumference and a relief at a surface of the roller; formingone of the embossments in the material web by the relief of the roller;placing the embossment in register with a printed motif present on thematerial web; automatically adjusting a position of the relief inrespect to the printed motif by varying the variable circumference;wherein the roller has at least first and second segment-shapedembossing elements, arranged along the variable circumference thereofand defining the relief, at least first and second intermediate spacesdisposed about the variable circumference between the at least first andsecond segment-shaped embossing elements; wherein the first and secondsegment-shaped embossing elements are automatically angularly adjustedrelative to one another by rotating one of the at least first and secondsegment-shaped embossing elements relative to another one of the atleast first and second segment-shaped embossing elements about an axisof the roller according to the printed motif, said at least first andsecond intermediate spaces defining distances relative to one anotheraccording to an angular adjustment of the at least first and secondsegment-shaped embossing elements; wherein in a first condition the atleast first and second intermediate spaces have generally a same value,wherein in a second condition such that the first segment-shapedembossing element is angularly adjusted about the axis at a first anglerelative to the second segment-shaped embossing element, the at leastfirst and second intermediate spaces have different values; wherein theat least first and second segment-shaped embossing elements each definean arc-shape.
 17. The method of claim 16, wherein the at least first andsecond segment-shaped embossing elements have a same shape and a samelength.
 18. The method of claim 16, further comprising the step ofsupplying the material web, or at least a surface thereof to be providedwith the embossments, to the roller in a heated condition, and arrangingthe roller in a cooled condition.
 19. The method of claim 16, whereinthe angular adjustment of the first segment-shaped embossing elementincludes the step of rotating the first segment-shaped embossing elementabout the axis such that a first end of the first segment-shapedembossing element is closer to a second end of the second segment-shapedembossing element than a second end of the first segment-shapedembossing element to a first end of the second segment-shaped embossingelement.
 20. A method for manufacturing a product having a surfaceprovided with embossments, comprising the steps of: bringing a materialweb into contact with a roller, the roller having a variablecircumference and a relief at a surface of the roller; forming one ofthe embossments in the material web by the relief of the roller; placingthe embossment in register with a printed motif present on the materialweb; automatically adjusting a position of the relief in respect to theprinted motif by varying the variable circumference; wherein the rollerhas at least first and second segment-shaped embossing elements,arranged along the variable circumference thereof and defining therelief, at least first and second intermediate spaces disposed about thevariable circumference between the at least first and secondsegment-shaped embossing elements; wherein the first and secondsegment-shaped embossing elements are automatically angularly adjustedrelative to one another by rotating one of the at least first and secondsegment-shaped embossing elements relative to another one of the atleast first and second segment-shaped embossing elements about an axisof the roller according to the printed motif, said at least first andsecond intermediate spaces defining distances relative to one anotheraccording to an angular adjustment of the at least first and secondsegment-shaped embossing elements; wherein the at least first and secondsegment-shaped embossing elements each define an arc-shape; wherein thefirst intermediate space is defined between the first end of the firstsegment-shaped embossing element and the second end of the secondsegment-shaped embossing element, and the second intermediate space isdefined between the second end of the first segment-shaped embossingelement and the first end of the second segment-shaped embossingelement, the first intermediate space having a shorter length than thesecond intermediate space.